


The Adventures of Cerberus

by SuperStitious18



Category: DC's Legends of Tomorrow (TV)
Genre: F/F, Fluff
Language: English
Status: In-Progress
Published: 2019-04-03
Updated: 2019-04-05
Packaged: 2020-01-04 11:31:09
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,086
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18342809
Author URL: https://archiveofourown.org/users/SuperStitious18/pseuds/SuperStitious18
Summary: The newest charge of the Time Bureau is Cerberus.Puppy Cerberus at that rate.What could possibly happen with a baby hellhound?





	1. Accidental Puppy Acquisition

**Author's Note:**

> A big thank you to @WardenRoot for beta-ing this for me!  
> Hope you enjoy!

Honestly, Ava doesn’t know what she expected when Mona came into her office squealing about a puppy Cerberus being in holding. 

At first she thought that she was just pulling her leg, but standing here and looking down at a sleeping three headed puppy told her otherwise. What the actual hell was the guard dog of Hell doing here and in puppy form of all things? Ava just could not believe what she was seeing despite the physical evidence in front of her face.

“What on earth?” Ava finally managed to say something, looking at the barely contained glee on Mona and Gary’s faces. “Why the hell do we have-?”

“Uh, agents found him terrorizing cats in 1871 Spain and it blew up in religious texts when the mythological Cerberus who was  _ thought _ to be just that. A, uh, myth.” Gary looked like he was about to burst at the seams. “Can we pet him? He looks so soft!”

“Yeah, can we Director Sharpe?” Mona joined her coworker in begging Ava to let them do as Gary had asked.

They were honestly going to give her a headache at this rate. If she were being completely honest, she already had a headache and their begging only made it worse. “No, you cannot pet him. Just… leave him alone?” Ava was seriously going to need alcohol to deal with this. But looking back down at the snoring Cerberus, she decided she was going to need the good stuff to handle this.

Gary and Mona’s attempted bargaining was interrupted by the dog suddenly shifting, stretching and yawning as he woke up. They cooed and fawned over the puppy who didn’t look all that thrilled to be bombarded by this. It was likely the combination of the lights, noises, smells and all the new things that was over stimulating the poor dog. 

“Gary! Mona!” Ava called their names, placing her hands on each of their collars and pulling them back a little. “Get back to your stations, I’ll assess the young… Cerberus from here,” Ava hesitated, still not believing this despite everything that led up to this point. The duo looked rather sad, much like kicked puppies if she wanted to think about that, before they left the room, stealing glances back at the cowering pup.

Once she was sure they were gone, she lowered the shield so she could look over their newest charge. Ava wrinkled her nose in disgust when she got a good whiff of the smell in the cage. A mixture of wet dog and literal Hell, she’d have to figure out a way to give him a bath before he got even more rank. 

She slowly approached Cerberus, trying to make herself as non-threatening as possible so she wouldn’t be a target. Even though the hellhound was a baby and honestly looked cuter than anything she had seen before, Ava knew better than to blindly trust something. She’d been burned too many time before by doing that. She definitely wasn’t about to be burned by a dog, of all things, if she could help it. Also, she might get burned literally if Cerberus can spontaneously combust like she was majorly worried about just from having heard a few field agents’ testimonies. 

Ava crouched down in front of the shaking dog, gently reaching forward so all three heads could sniff her hand. If they reacted badly, things would have to proceed a lot differently than she was hoping for. She just wanted things to go smoothly for once in her damn life.

“Hey there, I know it’s kind of scary being in a big new world with lots of strange, new things. It’s okay though, see?” Ava gently touched the middle head’s snout, gently stroking the greasy fur. The change was almost immediately noticeable as all the dog just suddenly relaxed and all heads were pushing in to get attention from Ava. “There you go, it’s not so bad is it? Being brave?” she unintentionally cooed, charmed by the happy faces she was seeing.

The small pup tried climbing in her lap the longer she sat there, trying to examine them and make sure they were 100 percent okay before being fed and left to rest. “No, no, no. You can’t be in my lap! You’re all dirty.” Ava scrunched up her nose, distaste clear all over her face at the thought of messing up her clean pantsuit. “You need a bath before you go anywhere. Ugh, Okay, wait here.” She placed them down, standing up and heading towards the door so she could figure out what she needed in order to get Cerberus clean.

She couldn’t believe this was a thing. They had the guard dog of the gates of Hell here in the Bureau and they were a  _ fucking puppy of all things. _ Ava thought that was the most absurd part of this whole fiasco as she raised the shields back in the cell and started to head to the control room. “I can’t believe this is happening,” she muttered to herself, looking over Cerberus’s new file, and started heading towards her destination. 

As she made her way through the Bureau halls, she noticed something rather strange about the agents she passed. They seemed torn between gawking at her or diving out of her way. The latter she was used to, the former? Not so much. It unnerved her more than anything else. Nevertheless, she had a mission and she was determined to see it through no matter how weird her agents were acting.

The last thing she was expecting were the Legend’s all crowding around Nate, Gary, and Mona and staring down at something on the screen. “What exactly are you all doing?” Ava asked, placing her hands on her hips and cocking an eyebrow at the group. They all startled and leapt away from the control hub, looking a little guilty and a lot surprised that she managed to sneak up on all of them.

“Uh, well, you see, we just wanted to show the Legends our newest arrival!” Nate tried to offer an explanation and was about to continue when he just started gawking at the area around Ava’s feet.

“What?” 

“Uh… Ava?” Sara was the one who actually pointed to what had everyone’s attention on her since she had left the cellblock.

Before anyone could say anything, Ava felt a small weight press against her ankle, almost startling her enough to where she would kick at whatever was touching her. She refrained from doing that and looked down to see Cerberus pressing against her leg, all three heads panting from the exercise they just got. They looked quite content, leaning against her with three sets of tongues lolling out of their heads and just basking in her presence. It was charming in a way, but they should be in their cell, not with her.

Cerberus noticed they had her attention, and their tail started wagging furiously, happy to be acknowledged by the tall human. “You are supposed to be in your cell.” Ava looked unimpressed, cursing inwardly that she didn’t check the containment field before leaving. “You are also very dirty and need to be cleaned off.” She wrinkled her nose at the grease smudges on the floor and how she was definitely going to have to give the janitors a bonus for dealing with a long trail of grime. 

“You didn’t let us play with him!” Gary looked offended that he didn’t get to pet the puppy while Ava had been followed and the one to say they needed to leave Cerberus alone.

“Because they were adjusting to a new area, Gary. You and Mona are like puppies yourselves, you two were just scaring them but didn’t see it.” Ava was slightly annoyed, she may have been a cat person primarily but that didn’t mean she wanted any dog to be uncomfortable. 

The two of them at least looked ashamed of themselves for overwhelming the young puppy and apologized to her. Mona went to apologize to Cerberus by offering her hand, but the dog scurried behind Ava, cowering and trembling at the attempted contact. That surprised everyone as Mona was extremely talented in dealing with magical creatures, getting them all to love her was almost effortless on her part. 

So it was quite strange when one didn’t immediately take to her.

“Oh, don’t be scared! I’m Mona! I’m going to be taking care of you while you’re here.” She tried to convince the puppy she had only good intentions, but Cerberus didn’t budge, looking around Ava’s leg and whimpering. “Do you think you can move, Director Sharpe? I’m gonna see if I can pet him.”

Ava did indeed move and walk a few steps away, but instead of Mona being able to touch them, Cerberus perked up all their ears and heads then toddled after the director. “Hey, no, you need to stay with Mona,” Ava protested, but they just sat at her feet, gazing up at her adoringly. “Mona, what are they doing?” she asked, hoping for an answer.

“Uhhh, I have no idea! I think Cerberus might be more of Nate or Charlie’s expertise? Maybe John?” Mona shrugged, standing upright and looking just as confused as Ava felt. 

“They’ve decided you are its master, that’s what it looks like to me,” Charlie piped up, looking amused from her place next to Zari. “Congratulations, you’re a mum now.”

Ava wrinkled her nose, looking between the now amused faces of the Legends and the happy, three-headed dog who seemed to be scooting closer to her legs. She largely preferred cats to dogs and she  _ had no idea what to do with a puppy Cerberus. _ It looked like she’d have to figure it out pretty damn quick if the way they were clinging to her was any indication.

However, Ava supposed there were worse things than having a goofy looking puppy imprint on you. Worse things than that indeed.


	2. A Day at the Office

**Summary for the Chapter:**

> Ava has to learn how to deal with Cerberus who just wants to be around her all the time. Antics ensue.

**Notes for the Chapter:**

> I hope you enjoy!

“Why is Cerberus in my office?” That was the first thing out of Ava’s mouth when she walked in to deal with paperwork. Seeing the small, black three-headed dog lazing on her chair had not been what she was expecting in the least. 

At the sound of her voice, Cerberus perked up and scrambled off the chair to pad over and greet Ava by plopping down in front of her and wagging their tail. She had to admit, that had a certain charm to it, being greeted by a creature who was thrilled to see her, but the fact of the matter was that they should be in a cell. They’d at least have various toys to play with and a place to sleep without worrying about other agents bothering them. Instead, they were here, in her office, looking thrilled that she was here and no doubt had been pestered by others.

“He kept whining and was sad so I brought him here!” Gary was entirely too cheerful for Ava’s taste but he looked so excited and proud of himself for thinking of a solution that she let it slide for right now. “He really likes you!”

Ava gave the puppy at her feet (they looked to be trying to nip and tug at her pants but they were failing miserably) a quick glance before she responded to him, “So it seems.” Next, she knelt down and gently patted the middle head before the other two started competing to get love from her. The big problem with that was that she only had two hands, so one head would be left out. “Hey, hey, I only have two hands,” she told them, feeling a little overwhelmed with all the love Cerberus was trying to give her.

By the time Ava was done and had stood up again, Gary had disappeared to wherever he liked to go and call it work. She shook her head, dismissing the odd man before leveling Cerberus with a stern look. “Behave.” They didn’t seem to understand the light threat and just all barked at her, their tail wagging even faster as Ava moved and they went to follow her. 

She sat in her chair, ready to start paperwork and get her work day started, when there was a small whine from her right. Looking down, she was greeted with three sets of puppy dog eyes and ears flattened against their skulls. Ava had no clue what they wanted, they couldn’t already have to go to the bathroom, right? She was positive they had already been fed and played with so she really had no clue what they wanted.

Until they started to try to jump in her lap. 

“Hey, no, no, no, no jumping in laps.” Ava pressed her hand against their chest, stopping their little hopping motions. She got a long, drawn out whine for saying that and the puppy dog eyes intensified. “I said no,” she said a little more firmly, pulling back, and Cerberus settled on the floor, looking extremely sad at the rejection. Ava set out to ignore them, she had paperwork she needed to do and she was already late starting on it because of the small distraction in her office.

The peace didn’t even last five minutes before she heard something being messed with in her office. She quickly glanced around for the source of the disturbance before locating Cerberus trying to get into the potted plants she kept around. “Hey! Hey no.” Ava got up, hurrying over to try and distract them from destroying her office plants. She gently pulled them away from the plants, narrowly avoiding getting licked in the face. “We don’t play with plants.” 

Ava moved them to a small puppy pen that had been set up by someone, most likely Mona, and she set them down, ignoring the sad whines that she got. “You can stay but I can’t have you distracting me every five minutes. I’m sorry but this is better than you going back to the cell since you seem so attached to me.” She paused before sitting down, giving them a stern look and getting happy shuffling in response. 

“Why are you so cute? I still don’t like dogs but you are ridiculously adorable,” Ava mused for a moment before fully settling down and setting out to read over reports. 

As much as she disliked the havoc the puppy caused before she could get started, Ava could admit that her office felt a lot nicer with a companion to keep her company. Also, logically, she knew she’d have to train them to not get into things and figure out ways to keep them entertained as they were a very intelligent being. That wouldn’t be an easy task to accomplish but maybe, just maybe she could figure out something.

If nothing else, she could ask Sara. She was a dog person, she should be able to help her with this. 

A small smile appeared on her face at the thought of her girlfriend. Things had been going well between them lately, especially with their resolve to keep their work and home lives separate. Plus, they’ve been communicating a lot better when something has been going on or just communicating in general. Ava knew she felt more secure in their relationship now than she had before and she only hoped Sara felt the same.

Especially if they were apparently going to be adopting a hellhound to keep with them.

It was around lunch time when she remembered the pup was in her office. Frantically, she got up to go check on them and relaxed only when she saw they were asleep, belly up and making soft snoring noises. Ava sighed, wondering to herself why she was so concerned over a magical creature. She gazed back down at Cerberus, who was starting to shift and wake up as if they sensed she was nearby, and she decided that maybe it was because she was going soft.

Happy yipping broke her out of her train of thought and she smiled as she saw Cerberus trying to hop up and reach her. “Well, maybe a break wouldn’t be so bad. I imagine you’d like to get out of the office.” Ava let them out and went to inspect the pet store bag Mona had dropped off a few hours ago while she had been neck deep in field reports. 

Inside the bag, she found a neon green harness, a leash, and three small collars that would go around each of their necks. Ava chuckled when she read the tags on the collars, all of them having her name and phone number on it. She wasn’t even sure it was a good idea to take Cerberus out in public but with meta humans and aliens, she was sure there were weirder things people have seen. “What do you think?” Ava asked Cerberus, laying out the items for the puppy to sniff.

It was amusing to watch them all pick a different thing to investigate. The middle head grabbed the leash that she held loosely in her hands, tugging on it and trying to pull it away from her. The other two noticed what was happening they joined in, trying to help in getting the leash in a game of tug ‘o war. 

Ava decided this was the best thing she’s seen or done in the past few days at the Bureau. She barely got to go home to spend time with Sara with how hectic everything had gotten, so just sitting on the floor and playing with a magical three-headed dog was an interesting way to unwind. 

“Alright.” She coerced the leash from their mouths and managed to wrangle the collars and harness on. Ava took a moment and checked that everything was tight and secure, as well as making a mental note to make a better harness for them as they looked uncomfortable. “Hmmm, I don’t think that’s gonna work… I’ll take the harness off if you think you can walk next to me?” 

She had no idea why she was trying to talk to a dog like they would understand her, but if she knew anything about magical creatures is that they were often more intelligent than humans gave them credit for. This would be a fun experiment, seeing if she could keep Cerberus from wandering off and following her instead. At the very least, it would be a good training exercise.

Ava tested it out by walking around her office a few times, rewarding Cerberus with lots of petting and treats when they managed to not get distracted. “Okay, it looks like you have it.” She smiled down at the puppy, enjoying the three happy grins she got in response. They were just too damn cute for her to dislike them. 

The walk seemed to be going well so far, she only had to call Cerberus back to her side twice and they looked happy with a wagging tail and panting a little as they tried to keep up with her long stride. Ava was glad everything was going well so far. She couldn’t exactly blame them for getting distracted by Gary running through the halls, something apparently biting him while Nate chased him, fully steeled up, and Mona behind them holding a crate. That was a headache she was not about to deal with while she was on break.

Checking the weather forecast, she decided it was a nice enough day to go out into the garden. It wasn’t too early to get Cerberus used to the outdoors. Ava held the door open for them, lightly encouraging them when she noticed they were hesitating on stepping down the two small steps leading outside. She cheered when they managed the steps, waddling around the garden now and sniffing  _ everything  _ they could. 

Ava got distracted by a phone call from Sara telling her that she was on her way with lunch and a few surprises. “I can’t wait to see you,” she said, letting her defenses down for a moment and exposing her softer side.

“I can’t wait to see you either. Where are you in the Bureau? I’ll meet you there.”

“In the garden, I decided it was too pretty of a day to be cooped up inside for lunch.” Ava knew what was coming next. Sara would tease her for going soft because she knew damn well that Ava would stay inside and miss lunch for work. It was only because of the puppy that she decided to do anything remotely like taking a break. 

“Uh huh, well, we can have lunch there then.” Sara’s voice told Ava that she knew exactly why Ava was where she was. “You’re right! 68 degrees and cloudy according to Gideon’s weather tracker, I’ll definitely be there soon.”

“Alright, I’ll be waiting and I love you.” 

“I love you too.” She swore she could hear the smile in Sara’s voice just from those few words and it made her light up, inside and out. 

Ava didn’t really want to hang up, she would have been content to stay there and just exist in the silence with Sara on the other end of the line but she knew that she would get here faster if she hung up. “Okay, I’ve got to check on Cerberus. See you soon, my love.” Only after she got a confirmation from Sara, did she hang up and turn to find said dog.

“Well, that’s interesting,” Ava said, looking extremely confused at the three-headed dog who was in an awkward position. One head had apparently found a bird and was barking it’s little head off trying to get to it but the rest of them weren’t exactly keen to go anywhere it seems. The middle head was trying to eat a flower but couldn’t get close enough to it with all the movement that the first head was doing. The third head had apparently found a stick and looked extremely content holding it in their mouth.

Then Cerberus took off, the rest of them finally agreeing that the bird was a hostile that needed to be destroyed. Ava had no idea how to deal with that. Did she leave them to their own devices and hope they didn’t ruin anything? Or did she follow them and make _ certain _ they wouldn’t get in trouble? They were still a puppy, they were bound to get into trouble, but she’d much rather the Bureau stay in one piece. 

When she heard a loud crash and a whining noise was when she took off running to go and try to find the mischievous Cerberus. Ava found them stuck in a grassy area where the concrete was too high for them to jump back onto it, and they were whining for her to come help. The crash was a result of them accidentally careening into a stone statue and knocking it over. 

Sighing, she straightened out the stature, which miraculously had not been broken, and then lifted the pup out of the small ditch. “I asked you earlier if you would behave.” Ava set out to chastise them but Cerberus was determined to lick her face, their whole body wriggling from the excitement. “Hey, wait, we agreed on no licking my face!” she yelped, trying to duck away from the heads that were stretching to reach her.

She was so busy dealing with that, she missed the sound of footsteps approaching her and she definitely missed the fact that it was Sara trying to not laugh while recording what was going on. 

“Should I come back later?” Ava heard her girlfriend ask and she almost dropped Cerberus but managed to cradle the puppy to her chest and avoid that. On the downside, she got a face full of puppy slobber and kisses from them that she had been trying to avoid. However, it didn’t seem that big of a deal when Sara was laughing at what was going on and came over to kiss the cheek that hadn’t been covered in saliva. 

Lunch with her girlfriend and trying to contain a baby hellhound was far better than staying in her office, doing paperwork and working herself ragged. This was a much better option indeed, especially when Sara made them all flower crowns, one for each of them and one for each of Cerberus’s heads. Being here with them made all the morning hassle worth it in the end.

**Author's Note:**

> Thank you so much for reading this! Please let me know what you thought or just yell at me on tumblr @superstitous19!


End file.
